1. Field of the Invention
The present invention relates to a sheet conveyance apparatus and to an image forming apparatus equipped with the sheet conveyance apparatus.
2. Description of the Related Art
Conventionally, in an image forming apparatus forming an image on a sheet, such as a printer, the sheet is fed from a feeding unit, and is conveyed along a sheet conveyance path. Then, an image is formed on the sheet, which is discharged. Herein, when conveying the sheet, the sheet may get stuck in the sheet conveyance path to cause a paper jam. When the paper jam occurs, it is necessary to perform jamming handling to remove the sheet which has caused the paper jam. Then, the user opens a jamming handling cover to expose the sheet conveyance path to the exterior, and performs jamming handling.
Japanese Patent Application Laid-Open No. 10-107940 discusses an image forming apparatus configured to display jamming handling operation procedures on an operation panel so that the user can smoothly perform the jamming handling.
However, when the user does not follow the jamming handling procedures displayed on the operation panel or when the jamming handling is performed in an improper manner, the sheet may suffer damage, with the result that the jamming handling takes time.
For example, when a paper jam occurs in a sheet while the sheet is being fed from a feeding cassette, jamming handling procedures are displayed to instruct the user to open the sheet conveyance path adjacent to the feeding cassette, and to remove the sheet that has jammed. However, if the user follows the erroneous jamming handling procedures and draws out the feeding cassette, the sheet may suffer damage. In particular, in the case where the feeding cassette drawing-out direction and the conveyance direction of the sheet from the feeding cassette cross each other, if the jammed sheet is stretched between the feeding cassette and the apparatus main body, the sheet will suffer damage such as rupture. Then, when the sheet thus suffers damage, a lot of time and effort is required of the user in performing the jamming handling.
In view of this, Japanese Patent Application Laid-Open No. 2005-263375 discusses an image forming apparatus equipped with a mechanism configured to restrict drawing-out of a feeding cassette so that the user is disabled to draw out the feeding cassette when a paper jam occurs in a sheet being fed from the feeding cassette.
The image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2005-263375 is equipped with a mechanism configured to electrically restrict the drawing-out of the feeding cassette based on the detection result of a sheet detection sensor configured to detect a residual sheet in a sheet conveyance path.
However, the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2005-263375 leaves room for an improvement. That is, the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2005-263375 is equipped with the mechanism configured to electrically restrict the drawing-out of the feeding cassette, so that, when the power of the apparatus main body is OFF, the feeding cassette may be drawn out by the user. Then, when the user follows the erroneous jamming handling procedures and draws out the feeding cassette, the sheet may suffer damage.